Air conditioner



23, 1953 K. E. MARSTELLER 3,

AIR CONDITIONER Filed Sept. 28, 1965 INVENTOR, Kf/Y/V'f/l f, Aid/$727164 United States Patent 3,364,989 AIR CONDITIONER Kenneth Edward Marsteller, Willow Grove, Pa., assignor to Philco Ford Corporation, a corporation of Delaware Filed Sept. 28, 1965, Ser. No. 490,992 3 Claims. (Cl. 165-122) ABSTRACT OF THE DISCLOSURE The blower wheel of a room air conditioner has an axial length longer than the Width of the discharge opening in the scroll housing. The eye of the scroll is especially formed and the discharge portion of the scroll is especially tapered toward the discharge opening to accommodate the longer blower wheel and to provide smooth transition to the narrower discharge opening.

This invention relates to air conditioners, and more particularly to the form and construction of the air inlet and discharge assembly of a centrifugal room air fan associated with the cooling coil of a room air conditioner.

Air conditioners of the aforementioned type are characterized by compactness of construction that limits, among other things, the width of the room air fan discharge opening, and consequently the axial dimension of generally cylindrical air impellers commonly used in such fans. In an air conditioner where such limitations as these prevail, in order to achieve higher air flow rates it has been conventional practice to increase the rotational velocity of the impeller. However, increases in rotational velocities have disadvantageously resulted in increased overall noise levels.

It is a general objective of this invention to provide fan means of the aforementioned type that is characterized by both operation at a low noise level and improved efiiciency in achievement of increased air flow rates.

In achievement of the foregoing general objective, the invention contemplates that air blower means associated with a room air conditioner be provided with a blower wheel that is substantially longer than the width of the blower discharge air opening, and that the blower housing air inlet and discharge assembly be specially formed and tapered to accommodate the longer blower Wheel and to provide a smooth transition to the relatively narrow air discharge opening, without changing the overall dimensions of the air conditioner.

The manner in which the foregoing as well as other objectives and advantages of the invention may best be achieved will be more clearly understood from a consideration of the following description, taken in light of the accompanying drawing in which:

FIGURE 1 is a perspective view of air conditioning apparatus embodying the invention;

FIGURE 2 is an elevational showing of the apparatus seen in FIGURE 1, with a part removed;

FIGURE 3 is a view, partly in section and with parts removed, looking downwardly on the air conditioner as seen in FIGURE 2, generally in the direction of arrows 33 applied to the latter figure; and

FIGURE 4 is an exploded view of a portion of the apparatus seen in FIGURES 2 and 3.

With more particular reference to the drawing, and first to FIGURES 1, 2 and 3, air conditioning apparatus embodying the invention preferably is of the relatively compact, room type comprising an outer cabinet 11 provided with a base member 12 that supports a refrigerating unit assembly including a compressor 13, a condenser coil 3,364,989 Patented Jan. 23, 1968 14, and an evaporator coil 15. The elements of the unit assembly are connected in the usual series refrigerant flow circuit by conduit means 14' and 15 and by capillary tube restrictor R. Compressor 13 and condenser coil 14 are disposed in a compartment separated from evaporator coil 15 by a vertically standing partition 16 that extends substantially centrally of the housing.

A decorative panel 18 (FIGURE 1) overlies the front of cabinet 11, and includes air inlet louvers 19 and outlet louvers 20 associated with air moving means housed within the cabinet and hereinafter to be more fully described. Panel 18 also includes an opening disposed for registry with a conventional control panel C associated with operating elements of the air conditioner. For convenience, panel 18 has been removed in each of FIGURES 2, 3, and 4.

A fan motor 17 is supported in the left hand region of partition 16 in such position and arrangement that its shaft 21 extends transversely of the partition. Motor shaft 21 drives fan means 22 at one end to induce flow of outdoor air over the condenser coil and compressor, and drives fan means 23, at the other end, to induce flow of indoor, or room, air over the evaporator coil.

Room air fan means 23 therefore is disposed laterally of evaporator coil 15, which is of the conventional fin and tube type, and is in air flow communication with the region about the evaporator coil by means of an air duct 24 formed in part by partition 16, as best seen in FIG- URE 3.

In especial accordance with the invention, and as seen to further advantage in FIGURE 4, room air fan means 23 comprises a blower wheel 25 of the socalled squirrel cage type that extends coaxially with motor shaft 21 and is surrounded by a scroll shaped housing 26 provided with an air discharge duct means provided with opening 27 and formed, collectively, by the fan cut-off 31, by the upper peripheral portion of the housing 26, by the evaporator coil end partition 34, and by an upper, vertically extending panel segment 35. For convenience of illustration, panel segment 35 has been shown in broken lines in its assembled position and in full lines in its exploded position.

A panel 33 is cooperably disposed with respect to the peripheral portion of housing 26 to enclose the outboard end of blower wheel 25, and has a circular opening 32, formed in an offset portion of the panel and comprising the fan inlet port aligned with the eye of blower wheel 25. The fan inlet port is in air flow communication with inlet louvers 19 provided in decorative panel 18. As is clear from FIGURES 3 and 4, blower wheel 25 extends axially for a distance that is greater than the width of the fan duct means and discharge opening 27. The relatively long blower wheel preferably has a blade density of unity (i.e. the ratio of blade area to circumferential area=1). I have found that this ratio affords optimum air flow rates characterized by reduced velocities over the blades. Panel 33 is especially formed to accommodate the relatively longer blower wheel, and further is tapered at 36 to provide a smooth transition of the housing from the fan inlet port to the narrower discharge duct means and the opening 27 that communicates with duct 24 leading to evaporator coil 15. Air discharged by the fan is caused to flow over evaporator coil 15, through rotatably adjustable louvers 20a in a sub-panel 28 overlying the evaporator coil, and finally through louvers 20 into the room or other region to be air conditioned.

Panel 33 conveniently is formed of a foamed plastic, of known type, molded in a single piece into the illustrated configuration. However, if desired it could be formed of bent sections of sheet metal, or even sheets of plastic material.

It will be appreciated that the disclosed noise reduction structure has particular utility in combination with the compact, side-by-side fan means 23 and evaporator coil 15 in the illustrated air conditioner. Advantageously, the inventive structure permits enlargement of the blower housing into unused space adjacent the evaporator coil. By way of example, the housing width in an air conditioner of this type has been extended to /2 inches from an original width of 4 /2 inches. In order to retain the original 4 /2 inch width of discharge opening, apertured panel 33 has been tapered, as seen portions thereof, in overlying registry with the extended blower wheel, to the discharge duct means and opening.

By extending the apertured panel portion of the blower housing to accommodate use of the longer blower wheel in the evaporator coil air flow circuit, it is possible advantageously to use the same speed motor while achieving an increased air flow rate. Moreover, since the same motor is used, the same condenser air fan can also be used.

I have found that the invention provides for a gentle squeezing of the air by the tapered panel, at noise levels less than would be expected. The construction also accommodates retention of the thin overall depth dimension of a room air conditioner while achieving increased air flow without the penalty of increased noise.

In comparison tests of apparatus utilizing conventional blower arrangements with apparatus embodying the invention, there was found to be a reduction in operating sound level of 7 dba for the latter. The sound levels were obtained and recorded, under semi-reverberant room with the microphone placed 3 ft. in front of the air discharge grill 20.

While a single preferred embodiment of the invention has been described, it will be understood that the invention is susceptible of use in air conditioning apparatus having slightly different coil and blower arrangements. In any event, such modifications are contemplated by the scope of the appended claims.

I claim:

1. A housing for a blowershaped outer wall, a substantially one lateral edge portion of said outer wall, a fan wheel having a first .portion rotatably mounted within the portion of said housing defined by said recited walls, and a second portion thereof extending axially beyond the free lateral edge portion of said outer wall opposite the recited one lateral edge portion, and panel means overlying the open side of said scroll-shaped outer wall and including device having a scrollat 36, from the extended surface identical conditions, in a flat side wall joined to a first, planar portion cooperatively disposed relative to portion recessed to receive the protruding portion of said;

wheel, said recessed portion defining an opening positioned in registry with the eye of said wheel, said recessed portion further including a surface region extending with angularity with respect to the plane of the eye of said Wheel and toward said first, planar portion of said panel means.

2. A housing according to claim 1, and characterized in that at least said second, recessed portion of said panel means is of molded, foamed-plastic construction.

3. In an air conditioner, the combination of a cooling element, and fan means for circulating air into heat exchange relation With said cooling element and discharging it into a space to be conditioned, said fan means comprising: a rotary impeller wheel of predetermined length; means defining a Wall adjacent one end of said wheel; a scroll of lesser Width than the length of said wheel and partially enclosing the latter, and panel means overlying the open side of said scroll, and including a first, planar portion cooperatively disposed relative to said scroll and said wall to form tially the width of said scroll, and a second, recessed portion receiving the protruding portion ,of said wheel, said second portion defining an opening positioned in registry with the eye of said wheel, said second portion further including a surface portion extending with angularity with respect to the plane of the eye of said wheel and toward said first planar portion of said panel means.

References Cited UNITED STATES PATENTS 1,495,873 5/1924 Schmelzer 230-127 2,984,089 5/1961 Whitsel 62-429 2,989,855 6/ 1961 Thompson 62296 3,131,236 4/1964 Beehler et al 230-127 FOREIGN PATENTS 1,322,069 2/1963 France.

ROBERT A. OLEARY, Primary Examiner.

T. W. STREULE, Assistant Examiner.

discharge duct means extending substan- 

